topic Cannot access LAN-zone interface from VPN-zone in Network Security

Cannot access LAN-zone interface from VPN-zone

Danny Cheng Chee Wah — Tue, 12 Mar 2019 03:43:22 GMT

Hi,

Referring to the topology below, I encounter a problem where I cannot reach Site B from Site A.

Below is the ping test performed.

FW_A (ASA5512-X)

1) Ping 10.60.186.69 >>> Success

2) Ping 192.168.88.2 >>> Success

3) Ping 192.168.88.6 >>> Success

4) Ping 10.60.187.1 >>> Fail

5) Ping 10.60.187.5 (Switch behind FW_B) >>> Success

RTR_A

* No access

RTR_B

1) Ping 192.168.88.6 >>> Success

2) Ping 10.60.187.1 >>> Fail

2) Ping 10.60.187.5 (Switch behind FW_B) >>> Success

FW_B (ASA5525-X)

1) Ping 192.168.88.5 >>> Success

2) Ping 192.168.88.1 >>> Success

3) Ping 10.60.186.70 >>> Success

4) Ping 10.60.186.81 >>> Success

5) Ping 10.60.186.85 (Switch behind FW_A) >>> Success

My main objective is to access FW_B 10.60.187.1 from LAN_A. Please advise what I need to check to be able to acieve this.

I was told that by default, I can only reach/access the ASA connected interface to my network. But if so, how am I able to reach FW_A LAN interface from FW_B. Anyone mind clearing my doubts?

P/S: The link between Site A and Site B is an IPVPN link, thus no VPN configuration needed on both FW_A and FW_B. Just listed that network portion as VPN-zone.

Thank you.

Regards,

Danny

Cannot access LAN-zone interface from VPN-zone

Marius Gunnerud — Mon, 10 Feb 2014 09:01:20 GMT

So you have a site to site VPN between FW_A and FW_B? Or is this an MPLS VPN setup? or something else?

Without seeing your configuration, by default you will not be able to ping the ASA inside interface over a site to site VPN. You will need to add the command managment-access to be able to reach the IP associated with the interface name.

But that you can not ping the inside switch could point to either a crypto ACL problem or a routing problem...depending on what your setup is.

Could you please explane in more detail your setup so that we can assist you further.

--
Please remember to rate and select a correct answer

Cannot access LAN-zone interface from VPN-zone

Danny Cheng Chee Wah — Mon, 10 Feb 2014 09:07:28 GMT

Marius,

It's just an IPVPN link by the provider, thus no VPN configuration done. Sorry for the confusion, but I was just naming that as VPN zone.

Firewall policies and routing should be correctly configured, because from RTR_B, I can ping across to the switch behind FW_B. It's just that I cannot ping to the FW_B LAN interface.

As from FW_A, I can ping all the hops until FW_B 192.168.88.6, but cannot reach to 10.60.187.1 (FW_B LAN) and 10.60.187.5 (Site B switch).

Regards,

Danny

Cannot access LAN-zone interface from VPN-zone

Marius Gunnerud — Mon, 10 Feb 2014 09:11:37 GMT

Each hop along the path would need a route to FW_B LAN. Are you able to ping FW_B LAN from RTR_A?

--
Please remember to rate and select a correct answer

Cannot access LAN-zone interface from VPN-zone

Danny Cheng Chee Wah — Mon, 10 Feb 2014 09:25:16 GMT

I don't have access to RTR_A, but from FW_A I can ping all the way to Site B switch. Hence, routing should be fine.

Both FW VPN zone security level is 50 and LAN zone security level is 100. Is it supposed that I can only ping to the connected interface of the firewall? For example, FW_A can only reach until FW_B VPN interface 192.168.88.6 and FW_B can only reach until FW_A VPN interface 10.60.186.70? If yes, I'm wondering how come FW_B can ping to FW_A LAN interface.

Regards,

Danny

Cannot access LAN-zone interface from VPN-zone

Marius Gunnerud — Mon, 10 Feb 2014 10:06:08 GMT

Is it supposed that I can only ping to the connected interface of the firewall?

No, this is not correct. The IPVPN configuration is done on the routers so all traffic that enters the routers will be sent over the VPN network...that includes traffic from the ASAs.

If you add the following command are you able to ping

icmp permit any inside

Where inside is the name of the interface that you are trying to ping

--
Please remember to rate and select a correct answer

Cannot access LAN-zone interface from VPN-zone

Danny Cheng Chee Wah — Tue, 11 Feb 2014 01:02:22 GMT

Tried that, but still not able to ping the FW_B LAN interface.

Regards,

Danny

Cannot access LAN-zone interface from VPN-zone

Marius Gunnerud — Tue, 11 Feb 2014 08:23:27 GMT

Could you post the full configuration (sanitised of course) of FW_A and FW_B please. It is the FW_B that is the interesting firewall, but would like to compare the two configurations for myself.

Are the firewalls running different versions?

--
Please remember to rate and select a correct answer